CANADIAN ASTRONOMERS PROVIDE FIRST IMAGES FROM A NEW
TELESCOPE "BIGGER THAN EARTH"

ST-HUBERT (Quebec), July 29 -- Canadian astronomers have a new tool
for studying the innermost secrets of quasars, black holes and other
mysterious objects in the universe. Using a new international telescope that
is effectively twice the size of Earth, scientists are now looking at the
skies and creating images of distant celestial objects with up to 100 times
the resolution of images created by the Hubble Space Telescope.

Launched in February 1997, the international VLBI Space Observatory
Project (VSOP) is the first to link radio telescopes on Earth with one in
space. Working together, they create a "virtual" mega-telescope dish that is
over 25,000 km wide and by far the most powerful imaging device ever created
for space astronomy.

"This was a golden opportunity for the Canadian Space Agency," said Dr.
Terry Hughes, a Program Scientist within the CSA's Space Science Program.
"Astronomers around the world now have a much sharper view of space thanks
to Canadian-made technology and expertise developed as part of this historic
program."

The Canadian Space Agency's (CSA) prime contribution to VSOP was to
develop new hi-tech instrumentation that could precisely match the data
downloaded from the VSOP satellite with that from the terrestrial telescopes.
In return for providing the hi-tech synchronization system, Canada's VSOP
astronomy team now receives access to all project data.

The Canadian VSOP science team is head by Dr. Peter Dewdney of the
National Research Council's Dominion Radio Astrophysical Observatory (DRAO)
in Penticton B.C. His co-investigators are Dr. Russ Taylor of the University of
Calgary and Dr. Wayne Cannon of York University and Institute for Space and
Terrestrial Science (ISAS) near Toronto.

The first Canadian images from VSOP emerged from a process that began on
May 25 when telescopes from Australia, South Africa, and Japan simultaneously
pointed at a remote quasar 9 billion light years away. Recordings of the
quasar's weak signal were sent to the Canadian VSOP science team in
Penticton and the University of Calgary, where they were digitally processed by
a specially designed supercomputer. After a number of trials, the team was
finally able to obtain the information needed to put together their first
image.

Dr. Russ Taylor made the first Canadian image in a grueling all night
session in his laboratory. The subject of the observations is the distant
quasar PKS 1055+018, a galaxy containing a mysterious central object
believed to be a super-massive black hole. The object is typical of those that
will be studied at resolutions up to 100 times that of the Hubble Space
Telescope. Hundreds of quasars, radio galaxies and pulsars will be imaged
with this mega-telescope over the satellite's lifetime.

The VSOP satellite, named Halca, was launched on Feb. 12 by Japan's
Institute of Space and Astronautical Science (ISAS) and is the first of its
kind. Tracking stations (operated by NASA, NRAO, and ISAS) on four continents
receive a continuous stream of data from the Halca satellite. The tracking
stations and the network of ground telescopes are equipped with the CSA's
high-tech tape recorders, which were built by ISTS. The recorded signals are
sent to one of three locations in Japan, Canada and the U.S., where a custom
computer called a "correlator" is used to combine the signals.

ISAS leads the international collaboration backed by Japan's National
Astronomical Observatory, NASA's Jet Propulsion Laboratory, the US National
Radio Astronomy Observatory (NRAO), the Canadian Space Agency, the
Australia Telescope National Facility, and the European Joint Institute for Very
Long Baseline Interferometry.

PHOTOGRAPHS:

A colorful 8 X 10 glossy image of the Halca satellite in Earth's orbit
working with ground-based telescopes is available today through CANPRESS.
The inset features the first Canadian VSOP image, a distant galaxy that is
suspected to harbour a supermassive black hole in its centre. If you wish, you
may prefer to download
the image electronically in a variety of sizes.

ADDITIONAL NOTES:

(1) The VSOP dish is a radio telescope, and not an optical telescope
like Hubble, so data is initially received in the form of radio
waves, not visual images. Data must first be converted into computer
bytes and from there they are used to create scientifically useful
images.
(2) Creating a telescope dish larger than Earth by placing one antenna
in space is possible because the resolution of a radio telescope is
dependent solely upon the distance between the farthest points that
make up the dish of the telescope. In fact, it was in Canada in 1967
that two entirely different telescope facilities (Algonquin Radio
Observatory in Ontario and Dominion Radio Astrophysical Observatory
in B.C.) were first combined in order to put this theory into
practice. Canadian scientists received an international award in
recognition of this accomplishment.

National Radio Astronomy Observatory

July 18, 1997

Astronomers Make First Images With Space Radio Telescope

Marking an important new milestone in radio astronomy history, scientists
at the National Radio Astronomy Observatory (NRAO) in Socorro, New
Mexico, have made the first images using a radio telescope antenna in
space. The images, more than a million times more detailed than those
produced by the human eye, used the new Japanese HALCA satellite,
working in conjunction with the National Science Foundation's (NSF) Very
Long Baseline Array (VLBA) and Very Large Array (VLA) ground-based
radio telescopes. The landmark images are the result of a long-term NRAO
effort supported by the National Aeronautics and Space Administration
(NASA).

"This success means that our ability to make detailed radio images of
objects in the universe is no longer limited by the size of the Earth," said
NRAO Director Paul Vanden Bout. "Astronomy's vision has just become
much sharper."

HALCA, launched on Feb. 11 by Japan's Institute of Space and
Astronautical Science (ISAS), is the first satellite designed for radio
astronomy imaging. It is part of an international collaboration led by ISAS
and backed by NRAO; Japan's National Astronomical Observatory; NASA's
Jet Propulsion Laboratory (JPL); the Canadian Space Agency; the Australia
Telescope National Facility; the European VLBI Network and the Joint
Institute for Very Long Baseline Interferometry in Europe.

On May 22, HALCA observed a distant active galaxy called PKS 1519-273,
while the VLBA and VLA also observed it. Data from the satellite was
received by a tracking station at the NRAO facility in Green Bank, West
Virginia. Tape-recorded data from the satellite and from the radio telescopes
on the ground were sent to NRAO's Array Operations Center (AOC) in
Socorro, NM.

In Socorro, astronomers and computer scientists used a special-purpose
computer to digitally combine the signals from the satellite and the ground
telescopes to make them all work together as a single, giant radio
telescope. This dedicated machine, the VLBA Correlator, built as part of the
VLBA instrument, was modified over the past four years to allow it to
incorporate data from the satellite. Correlation of the observational data
was completed successfully on June 12, after the exact timing of the
satellite recording was established. Further computer processing produced
an image of PKS 1519-273 -- the first image ever produced using a radio
telescope in space.

For Jim Ulvestad, the NRAO astronomer who made the first image, the
success ended a long quest for this new capability. Ulvestad was involved
in an experiment more than a decade ago in which a NASA communications
satellite, TDRSS, was used to test the idea of doing radio astronomical
imaging by combining data from space and ground radio telescopes. That
experiment showed that an orbiting antenna could, in fact, work in
conjunction with ground-based radio observatories, and paved the way for
HALCA and a planned Russian radio astronomy satellite called RadioAstron.

"This first image is an important technical milestone, and demonstrates the
feasibility of a much more advanced mission, ARISE, currently being
considered by NASA," Ulvestad said.

The first image showed no structure in the object, even at the extremely
fine level of detail achievable with HALCA; it is what astronomers call a
"point source." This object also appears as a point source in
all-ground-based observations. In addition, the 1986 TDRSS experiment
observed the object, and, while this experiment did not produce an image, it
indicated that PKS 1519-273 should be a point source.

"This simple point image may not appear very impressive, but its beauty to
us is that it shows our entire, complex system is functioning correctly. The
system includes not only the orbiting and ground-based antennas, but
also the orbit determination, tracking stations, the correlator, and the
image-processing software," said Jonathan Romney, the NRAO astronomer
who led the development of the VLBA correlator, and its enhancement to
process data from orbiting radio telescopes. "We would be skeptical of a
complex image if we had not been able to obtain a good point image first,"
Romney added.

A second observing target, the quasar 1156+295, observed on June 5,
made a more interesting picture. Seen by ground-based radio observatories,
this object, at a distance of 6.5 billion light years, has been known to show
an elongation in its structure to the northeast of the core. However, seen with
the space-ground system, it is clearly shown to have both a core and a
complex "jet" emerging from the core. Such jets, consisting of subatomic
particles moving near the speed of light, are seen in many quasars and
active galaxies throughout the universe. In fact, 1156+295 is one of a class
of objects recently found by NASA's Compton Gamma-Ray Observatory to
exhibit powerful gamma-ray emission; such objects are among the most
compact and energetic known in the universe.

"By showing that this object actually is a core-jet system, HALCA has
produced its first new scientific information, and demonstrates its imaging
capabilities for a variety of astrophysical investigations," Romney said.
"This image shows that the jet extends much closer to the core, or 'central
engine' of the quasar than is shown by ground-only imaging," Romney
added.

"This is an exciting and historical achievement for radio astronomy," said
Miller Goss, NRAO's VLA/VLBA Director. "At NRAO, we have seen our
colleagues -- scientists, electrical engineers, computer programmers and
technicians in Socorro and Green Bank -- work for years on this project.
Now, they can take pride in their success."

Radio astronomers, like astronomers using visible light, usually seek to
make images of the objects at which they aim their telescopes. Because
radio waves are much longer than light waves, a radio telescope must be
much larger than an optical instrument in order to see the same amount of
detail. Greater ability to see detail, called resolving power, has been a
quest of radio astronomers for more than half a century.

To see a level of detail equal to that revealed by optical telescopes would
require a radio-telescope dish miles across. In the 1950s, British and
Australian scientists developed a technique that used smaller,
widely-separated antennas, and combined their signals to produce
resolving power equal to that of a single dish as large as the distance
between the smaller dishes. This technique, called interferometry, is used
by the VLA, with 27 antennas and a maximum separation of 20 miles, and
the VLBA, with 10 antennas and a maximum separation of 5,000 miles.
Systems such as the VLBA, in which the antennas are so widely separated
that data must be individually tape-recorded at each site and combined after
the observation, are called Very Long Baseline Interferometry (VLBI) systems.
VLBI was developed by American and Canadian astronomers and was first
successfully demonstrated in 1967.

The VLBA, working with radio telescopes in Europe, represents the largest
radio telescope that can be accommodated on the surface of the Earth. With
an orbit that carries it more than 13,000 miles above the Earth, HALCA,
working with the ground-based telescopes, extends the "sharp vision" of
radio astronomy farther than ever before. Using HALCA, radio astronomers
expect to routinely produce images with more than 100 times the detail seen
by the Hubble Space Telescope.

Astronomers around the world are waiting to use the satellite to seek
answers to questions about some of the most distant and intriging objects
in the universe. As much as one-third of the VLBA's observing time will be
devoted to observations in conjunction with HALCA. Over the expected
five-year lifetime of HALCA, scientists hope to observe hundreds of
quasars, pulsars, galaxies, and other objects.

Launched from Japan's Kagoshima Space Center, HALCA orbits the Earth
every six hours, ranging from 350 to 13,200 miles high. The 1,830-pound
satellite has a dish antenna 26 feet in diameter. The antenna, folded like an
umbrella for the launch, was unfolded under radio control from the ground
on Feb. 26. The antenna was pointed toward PKS 1519-273 after a three-
month checkout of the spacecraft's electronics, computers and guidance
systems.

HALCA observations represent a true international scientific collaboration.
In addition to the HALCA spacecraft, built, launched, and operated by
Japan's ISAS, the participation of a large number of ground-based radio
telescopes is also essential. NRAO's VLBA and VLA instruments, including
the VLBA correlator, will be a vital component of this collaboration. Other
radio telescopes in the U.S., Japan, Europe, and Australia, also will
participate.

NRAO's facility at Green Bank, WV, is one of five tracking stations where
the data collected on the spacecraft are received and recorded. Another is
at an ISAS facility in Japan, and JPL operates three additional tracking
stations, in California, Australia, and Spain. JPL also collects information
from all tracking stations to determine the very accurate spacecraft orbit
necessary to reduce these observations.

The NRAO Space VLBI efforts in Socorro and Green Bank were supported
by funding from the National Aeronautics and Space Administration. The
National Radio Astronomy Observatory is a facility of the National Science
Foundation, operated under cooperative agreement by Associated
Universities, Inc.

IMAGE CAPTIONS:
[NOTE -- The images can be found at the NRAO's anonymous ftp site,
at: ftp.aoc.nrao.edu They are in the pub/press directory.]
1519-273.gif -- Active galaxy (PKS 1519-273) as imaged with HALCA
satellite, along with the National Science Foundation's VLBA and VLA
ground-based radio telescopes. This is the first VLBI image ever made
using an orbiting radio-astronomy satellite.
----------------------------------------------------------------------------
1519_ground.gif -- The same active galaxy as seen with ground-only radio
telescopes. This image is to the same scale as the space-ground image.
----------------------------------------------------------------------------
1156+295.gif -- The quasar 1156+295 as seen using the HALCA satellite
in conjunction with the VLBA. This image shows the quasar's core, bottom
right, and a jet of subatomic particles emerging from the core toward the
top left.
----------------------------------------------------------------------------
1156_ground.gif -- Ground-only radio image of 1156+295, showing much
less detail. This image is not to the same scale as the space-ground image;
if at the same scale it would be larger.
----------------------------------------------------------------------------

SKY & TELESCOPE NEWS BULLETIN

FEBRUARY 14, 1997

SPACE INTERFEROMETER LAUNCHED

The VLBI Space Observatory Programme's MUSES B satellite was launched
from Kagoshima Space Center in Japan on February 12th in the first
tryout of the powerful new M-5 rocket. Once in space, the spacecraft
was renamed Haruka, which means "far away," a nod to the 21,000-
km-high apogee of its highly elongated orbit. Haruka's 8-meter-
wide radio antenna will serve as one element of an interferometer with
a diameter bigger than the Earth. Ground-based antennas on five
continents will also participate in the observations, scheduled to
begin in May after an initial checkout of the satellite. The
telescopes will make high-resolution radio images of maser sources in
galactic star-forming regions and of quasars in other galaxies.

LAUNCH WILL CREATE A RADIO TELESCOPE LARGER THAN EARTH

NASA and the National Radio Astronomy
Observatory are joining with an international
consortium of space agencies to support the launch of
a Japanese satellite next week that will create the
largest astronomical "instrument" ever built -- a
radio telescope more than two-and-a-half times the
diameter of the Earth that will give astronomers their
sharpest view yet of the universe.

The launch of the Very Long Baseline
Interferometry (VLBI) Space Observatory Program (VSOP)
satellite by Japan's Institute of Space and
Astronautical Science (ISAS) is scheduled for Feb. 10
at 11:50 p.m. EST (1:50 p.m. Feb. 11, Japan time.)

The satellite is part of an international
collaboration led by ISAS and backed by Japan's
National Astronomical Observatory; NASA's Jet
Propulsion Laboratory (JPL), Pasadena, CA; the
National Science Foundation's National Radio Astronomy
Observatory (NRAO), Socorro, NM; the Canadian Space
Agency; the Australia Telescope National Facility; the
European VLBI Network and the Joint Institute for Very
Long Baseline Interferometry in Europe.

Very long baseline interferometry is a technique
used by radio astronomers to electronically link
widely separated radio telescopes together so they
work as if they were a single instrument with
extraordinarily sharp "vision," or resolving power.
The wider the distance between telescopes, the greater
the resolving power. By taking this technique into
space for the first time, astronomers will
approximately triple the resolving power previously
available with only ground-based telescopes. The
satellite system will have resolving power almost
1,000 times greater than the Hubble Space Telescope at
optical wavelengths. The satellite's resolving power
is equivalent to being able to see a grain of rice in
Tokyo from Los Angeles.

"Using space VLBI, we can probe the cores of
quasars and active galaxies, believed to be powered by
super massive black holes," said Dr. Robert Preston,
project scientist for the U.S. Space Very Long
Baseline Interferometry project at JPL. "Observations
of cosmic masers -- naturally-occurring microwave
radio amplifiers -- will tell us new things about the
process of star formation and activity in the heart of
other galaxies."

"By the 1980s, radio astronomers were observing
the universe with assemblages of radio telescopes
whose resolving power was limited only by the size of
the Earth. Now, through a magnificent international
effort, we will be able to break this barrier and see
fine details of celestial objects that are beyond the
reach of a purely ground-based telescope array. We
anticipate a rich harvest of new scientific knowledge
from VSOP," said Dr. Paul Vanden Bout, Director of NRAO.

In the first weeks after launch, scientists and
engineers will "test the deployment of the reflecting
mesh telescope in orbit, the wide-band data link from
the satellite to the ground, the performance of the
low noise amplifiers in orbit, and the high-precision
orbit determination and attitude control necessary for
VLBI observations with an orbiting telescope,"
according to Dr. Joel Smith, manager of the U.S. Space
VLBI project at JPL. Scientific observations are
expected to begin in May.

The 26-foot diameter orbiting radio telescope
will observe celestial radio sources in concert with a
number of the world's ground-based radio telescopes.
The 1,830-pound satellite will be launched from ISAS'
Kagoshima Space Center, at the southern tip of Kyushu,
one of Japan's main islands, and will be the first
launch with ISAS' new M-5 series rocket.

The satellite will go into an elliptical orbit,
varying between 620 to 12,400 miles above the Earth's
surface. This orbit provides a wide range of
distances between the satellite and ground-based
telescopes, which is important for producing a high-
quality image of the radio source being observed. One
orbit of the Earth will take about six hours.

The satellite's observations will concentrate on
some of the most distant and intriguing objects in the
universe, where the extremely sharp radio "vision" of
the new system can provide much-needed information
about a number of astronomical mysteries.

For years, astronomers have known that powerful
"engines" in the hearts of quasars and many galaxies
are pouring out tremendous amounts of energy. They
suspect that supermassive black holes, with
gravitational fields so strong that not even light can
escape them, lie in the centers of these "engines."
The mechanism at work in the centers of quasars and
active galaxies, however, remains a mystery. Ground-
based radio telescopes, notably NRAO's Very Long
Baseline Array (VLBA), have revealed fascinating new
details in recent years, and VSOP is expected to add a
wealth of new information on these objects, millions
or billions of light-years distant from Earth.

Many of these same objects act as super-powerful
particle accelerators to eject "jets" of subatomic
particles at nearly the speed of light. Scientists
plan to use VSOP to monitor the changes and motions in
these jets to learn more about how they originate and
interact with their surroundings.

The satellite also will aim at regions in the
sky where giant collections of water and other
molecules act as natural amplifiers of radio emission
much as lasers amplify light. These regions, called
cosmic masers, are found in areas where new stars are
forming and near the centers of galaxies.
Observations can provide the detail needed to measure
motions of individual maser "spots" within these
regions, and provide exciting new information about
the star-forming regions and the galaxies where the
masers reside. In addition, high-resolution studies
of cosmic masers can allow astronomers to calculate
distances to them with unprecedented accuracy, and
thus help resolve continuing questions about the size
and age of the universe.

The project is a major international
undertaking, with about 40 radio telescopes from more
than 15 countries having committed time to co-observe
with the satellite. This includes the National
Science Foundation's Very Long Baseline Array (VLBA),
an array of 10 telescopes spanning the United States
from Hawaii to Saint Croix; NASA's Deep Space Network
(DSN) sites in California, Spain, and Australia; the
European VLBI Network, more than a dozen telescopes
ranging from the United Kingdom to China; a Southern
Hemisphere array of telescopes stretching from eastern
Australia to South Africa; and Japan's network of
domestic radio telescopes.

In the United States, NASA is funding critical
roles in the VSOP mission at both JPL and NRAO. JPL
has built an array of three new tracking stations at
its DSN sites in Goldstone, CA; Madrid, Spain; and
near Canberra, Australia. A large existing tracking
station at each of these sites has also been converted
to an extremely sensitive radio telescope for
simultaneous observations with the satellite. JPL
also is providing precision orbit determination,
scientific and operational planning support to the
Japanese, and advice to U.S. astronomers who wish to
observe with the satellite. NRAO is building a new
tracking station at Green Bank, WV; contributing
observing time on the VLBA array of telescopes;
modifying existing data analysis hardware and
software, and aiding astronomers with the analysis of
the VSOP data. Much of the observational data will be
processed at NRAO's facility in Socorro, NM, using the
VLBA Correlator, a special purpose high-performance
computer designed to process VLBI data.

VSOP is the culmination of many years of
planning and work by scientists and engineers around
the world. Tests using NASA's Tracking and Data Relay
Satellite System (TDRSS) proved the feasibility of
space VLBI in 1986. Just last year, those old data
were used again to test successfully the data-
reduction facilities for VSOP.

JPL manages the U.S. Space Very Long Baseline
Interferometry project for NASA's Office of Space
Science, Washington, DC. The VLBA, headquartered in
Socorro, NM, is part of the National Radio Astronomy
Observatory, a facility of the National Science
Foundation, operated under cooperative agreement by
Associated Universities, Inc.